Electron tube



21, M H LQUGHRIDGE ELECTRON TUBE Filed May 51, 1929 2 Sheets-Sheet lINVENTOR.

F. l 1 3g /rj) a 49 7 BY W A TTORNEY.

ELECTRON TUBE Filed May 51, 1929 2 Sheets-Sheet 2 INVENTOR.

A TTORNEY.

Patented July 21, 1936 UNITED STATES PATENT OFFICE Claims.

This invention relates to electron tubes and has for an object toprovide electron tubes for controlling a plurality of independentcircuits; to control a plurality of independent circuits selectively andto introduce characteristics into said circuits.

Another object of the invention is to provide an electron tubecontrolling a plurality of independent circuits each of which operatesat a dif- 19 ierent voltage, or has different current capacities.Another object of the invention is to provide an electron tube with aplurality of independent anodes and cathodes with supporting meanstherefor.

15 Other objects of the invention will appear from the followingspecification and the accompanying drawings forming part thereof,selected to show a form of the invention and, in which,

Fig. 1 is a sectional elevation of an electron go tube or circuitclosing device constructed according to this invention; Fig. 2 is anelevation of the base of the electron tube; Fig. 3 is a plan view of themounting with the electron tube removed; Fig. 4 is a cross section online 4 of the electron u, tube in Fig. 1; Fig. 5 is a cross section online 5 of the electron tube in Fig. 1, and Fig. 6 is a circult diagramshowing one application of the invention.

The mounting is provided with a row of bindgo ing posts or terminals andhaving a conical depression in the center and a plurality of spacedcontact members arranged in this depression which are electricallyconnected with the binding posts. This mounting is also provided with aas socket located in the axial center of the depression which may be ofthe screw socket variety used for electrical outlets and which has itsterminals connected with a pair of the binding posts.

The electron tube or circuit controlling device 40 is provided with aconical base to match the conical depression of the mounting and isprovided with spaced contact members to register with the contactmembers of the mounting. This base terminates in a cylindricalprojection which has a locking engagement with the mounting as the tubeis partially rotated. This rotation brings the contacting members intoengagement and tha'eby establishes the circuit from the binding posts tothe circuit controlling members within the tube. The base of the tube iscylindrical in form and is hollow to receive the projecting socket ofthe mounting and to receive the heating element of the tube when anexterior heating ele- Ji mentisused.

In the tube an exterior heating element is used comprising a coilenergized with alternating cure rent which, by induction, heats thecathode of the tube; however, the invention is of general applicationand this mounting of the heating element is not confined to tubes ofthis particular type and may be used with other devices or a similarcharacter.

One of the main purposes of this invention is to be able to control aplurality of independent cir- 10 cults by the energy in another circuitsimilar, for instance, to a multicontact relay in which the energy inthe relay coil controls an armature which in turn controls severalcontact fingers, each controlling independent circuits. For this purposea plurality of cathodes with corresponding anodes are provided in thetube and suitably separated from each other, while all of the cathodesare heated by a common heating element.

Each of the' sets of anodes and cathodes may be of difierent areas andmay be differently spaced with the object of varying the resistance ofthe circuit controlled by the device and making the device selective inits control of various apparatus. This enables a single tube to secureresults that heretofore have required several tubes and brings theseresults under a single control through the heating element. The presentapplication is limited to the construction or the electron tube.

The mounting In the drawings, ii is the mounting which is preferablycircular in shape and is supported on a flange 2. The binding posts iiiare provided around the top outer edge and a conical depression isformed in the center in steps or ledges as shown and upon which thechannel contact members 22, 2,3, 24, and 25, are provided at one sideand corresponding contact members 22, 23, 24 and 25 are provided at theopposite side of these ledges. These contact members are connected withthe binding posts i3 as indicated at 25a and 25b, Fig. 1. The conicaldepression terminates in the cylindrical projection M which may beconnected with the walls ll of the mounting by the webs 15. In thecenter 0! this projection the socket I6 is provided having a screw shelll1 and a central contact is connected with a pair of the binding postsby means not shown in the drawings. Apertures are provided in themounting at IQ for ventilating the space a and providing an aircirculation through the outlet b in the center of the device. Theheating coil or induction coil 2i mounted on the stem 2|! is screwedinto the 55 socket l8 and is thus independently supported by themounting.

The electron tube The circuit controlling device is provided with aconical shaped base 28 which matches the conical depression in themounting being provided with ledges 21, 28, 28, and 88, upon which thecontact members 8|, 82, 88, and 88, are mounted at 38. When in thisposition the base is supported by the annular ledge 88a and the tube isvertically positioned in the mounting as the lugs 88 engage the inclinedface of the mounting at 38. Each tube device may be constructed withcertain internal characteristics which make it desirable that allreplacement tubes shall have corresponding characteristics and, for thispurpose a ledge 81 may be provided in the mounting to register with thegroove 81 in the lug 88 thereby preventing improper tubes from beingused in replacements. It will be noted that the channel contact memberson the mounting extend for approximately 90 of the circle and thecontact members on the base 28 are somewhat less than 90 so that thesecontact members are brought into engagement with a knife-switch contactas the tube is inserted in the mounting and locked therein by a rotationof 90. A knurled collar is provided at 88 for rotating the base.

The electron tube comprises the evacuated bulb so having an open centralcore 4| preferably opening by the tube 42 to the atmosphere at the upperend for ventilating purposes. 'I'hiscore is sectioned as shown by theflanges 42, 44, 45, 88 and 41 and between each of these flangesindependent sets of electrodes are mounted. 7 These comprise the cathode48 and the anode 48 in the top section, the cathode i0 and the anode 5|in the second section; the cathode 52, the anode 58. in the thirdsection, and the cathode 55 and the anode 58 in the bottom section. Itwill be noted that all the cathodes are aligned adjacent to the heatingcoil 2|. These cathodes are preferably made of iron and are heated byeddy currents induced in this iron from the current in the coil -2 I.

The cathodes are thus uniformly heated by the coil 2| and are preferablyspaced from the core of the tube to avoid overheating this core.

It will be noted that the electrodes in theupper section are longer thanthose .in the following section and correspondingly the length of theelectrodes is reduced from the top to the bottom sec tions; also it willbe observed that the electrodes in the upper section are spaced nearerto each other than in the following section and the spacing of theelectrodes is correspondingly increased from the top to the bottomsections. This is a matter of choice in the design of the tube in whichelectrons and therefore a larger current while the the larger areasprovide for a greater emission of increased spacing between theelectrodes increases the resistance and requiresv a higher voltage onthe operating circuits. As the capacity of a tube of this kind isdetermined by the, area of the cathode, by the distance between thecathode and the anode and by the material used in the manufacture of theelectrodes, it is apparent that circuits can be selectively controlledby each sec- -tion of the tube. For instance. thesmaller electrodes arenot suitable for conducting a large current and a current of .lowvoltage cannot be 5 established between the widely spaced electrodes.These electrodes are connected to the contact members in the conicalbase as illustrated in Fig. l, by conductor 88, connecting cathode 55with 24; conductor 58, connecting anode 56 with the contact member 84'and conductor connecting the grid 51 in the lower section with a contactin the base not shown but registering with contact 8| in the mountingwhen the tube is in place and similarly, the grid 88 connects withcontact plate 82 when the tube is in place, contacts 8| and 62 beingconnected with the terminals l8. The grid is preferably made from avertically arranged coil as indicated in Fig. 5.

The circuit diagram 12, pole changing switch 68 and battery 68. It .willbe noted that wire 12 connected to one side of the battery connects tothe anode l8 and to the cathode 50 so that when the pole changing switchso is in one position a circuit will be establl lished to energize thetranslating device 81 and no circuit will be establshed to thedevice 18until the pole changing switch is reversed when i1 is deenergized and I8is energized. The device I4 may be more sensitive than the device 81 andtherefore responsive to the lower current value between the electrodes50 and 8|. i

The transformer 15 energizes the mains l8 and II, the translating device18 connects to II and by wire 18 connects to the cathode S2 and from theanode 52 completes the circuit to wire I8. Th Dolyphase relay 80 has awinding 8| connected to the main l1 and is connected by wire 82 with thecathode and through anode 55 connects to the opposite main 18. Anotherphase of 50 this relay 83 connects between the mains l8 and II as shown.It will be observed from the arrangement shown that all the circuitscontrolled by the tube are controlled by the heating coil 2| beinterrupted while the controlling circuits of 81 and M are selectivelycontrolled by switch 88 when the switch 88 is closed; it will also benoted that the circuit of II is controlled by the grid 81, conductor 84and switch so that this circuit maybe interrupted by opening switch 85when the coil 2| is energized without aflecting the op eration of theother circuits controlled by the tube.

It will be noted that the combination of the mounting with the electrontube provides a de-' vice for controlling circuits which iscomparatively lowin cost. light in weight and which enables the mountingto be installed separately from the circuit controlling device. Thespace currentdevice has no moving parts, will operate in any position,and is not influenced by vibration. The interruption ofthe circuitdepends upon the coolingofthecathodmwhiehmaymake-thedevice26 aoaaiaaslow acting or the circuit may be controll by the grid which is quickacting.

Having thus described my invention, 1 m...

1. An electron tube comprising an evacuated vessel, a pair of cathodesand anodes in said vessel, a stepped conical base on said vesseldiametrically opposed contactmembers on each step of said base and meanselectrically connecting each of said anodes and cathodes with one ofsaid contact members.

2. An electron tube comprising an evacuated vessel having a centralnon-evacuated hollow stem, a plurality of pairs of annular anodes andcathodes spaced about said stem and a heating element located in saidhollow stem..

3. An electron tube comprising an evacuated vessel having a tubularnon-evacuated hollow stem with ledges on the tube projecting into saidvessel. cathodes located on said stem between said les and a heatingelement located in said nonevacuated stem. v

4. An electron tube comprising an evacuated vessel having a hollow,non-evacuated stem of insulation, a plurality of pairs of annular anodesand cathodes spaced about said stem and formed in different diameters,ledges projecting from said stem between said pairs corresponding tosaid diameters and a heating element located in said hollow stem.

5. An electron tube comprising a cylindrical evacuated vessel formed incontinuation with a non-evacuated hollow central stem, means on saidstem ior supporting a plurality o! annular cathodes in said vessel andmeans in said hollow stem for heating said cathodes.

MATTHEW H. IDUGBRIDGE.

